<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8"/>
  <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
  <title>Document</title>
</head>
<body>
  <div><button id="btn">click</button></div>
  <script type="module">
    document.querySelector('#btn').addEventListener(
      'click',
      () => {
        import('./index.js').then((value) => {
          console.log(value.default(5, 6))
        })
      },
      false
    )
  </script>
</body>
</html>